package com.example.netty.http;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.*;
import io.netty.util.CharsetUtil;

import java.net.URI;

/**
 * 说明
 * 1. 该类是 ChannelInboundHandlerAdapter 的子类
 * 2. HttpObject 客户端和服务器端相互通讯的数据被封装成 HttpObject
 */
public class TestHttpServerHandler extends SimpleChannelInboundHandler<HttpObject> {
    /**
     * 读取客户端数据
     * @param ctx
     * @param msg
     * @throws Exception
     */
    @Override
    protected void channelRead0(ChannelHandlerContext ctx, HttpObject msg) throws Exception {
        // 判断 msg 是不是 httprequest 请求
        if (msg instanceof HttpRequest) {
            // 多个浏览器有多个 pipleline 和 Handler。刷新浏览器，也会产生新的 pipliline 和 handler
            System.out.println("ctx 类型是 " + ctx.getClass());
            System.out.println("pipeline hashcode" + ctx.pipeline().hashCode() +
                    "TestHttpServerHandler hash= " + this.hashCode());

            System.out.println("msg 类型 = " +msg.getClass());
            System.out.println("客户端地址 = " + ctx.channel().remoteAddress());

            HttpRequest httpRequest = (HttpRequest) msg;
            // 获取到 url ，过滤指定字符串
            URI uri = new URI(httpRequest.uri());
            if ("/favicon.ico".equals(uri.getPath())) {
                System.out.println("请求了 /favicon.ico，不作响应");
                return;
            }


            // 回复信息给浏览器 【http 协议】
            ByteBuf content = Unpooled.copiedBuffer("hello, 我是服务器", CharsetUtil.UTF_8);
            // 构造一个 http 的响应，即 httpResponse
            FullHttpResponse httpResponse = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK, content);

            httpResponse.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/plain")
                    .set(HttpHeaderNames.CONTENT_LENGTH, content.readableBytes());

            // 将构建好 response 返回
            ctx.writeAndFlush(httpResponse);
        }
    }
}
